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Particulate matter has important influences on premature human mortality. Diesel particulate filter is one of the most effective means to reduce particulate matter in exhaust gas. In order to study the 3-D flow characteristics of diesel particulate filter porous structure, lattice Boltzmann method is used to study the flow and heat transfer characteristics of different structures. In some software, the spherical structure is used as diesel particulate filter porous structure. In paper, the spherical structure, the quartet structure generation set structure, and the computer tomography technique structure are constructed. The computer tomography technique structure is constructed by the serial sections of diesel particulate filter porous structure. The flow and heat transfer characteristics in different structures were simulated by lattice Boltzmann method. The 3-D computer tomography technique structure is constructed by superposing the serial section data of diesel particulate filter. The results show that the pressure gradient and temperature gradient of structures are greatly affected by the structure. The pressure gradient and temperature gradient of the spherical structure is the lowest. The spherical structure and the quartet structure generation set structure are different from the porous structure of diesel particulate filter in pressure gradient and temperature gradient. By comparing different structures, it can be seen that although the pressure gradients of the computer tomography technique structure and the quartet structure generation set structure are similar, the temperature gradient of the two structures are more different. [ABSTRACT FROM AUTHOR]

The 3-D mixed convective heat transfer inside a ventilated cavity partially heated is studied numerically by using control volume method. The heating square portion similar to the integrated electronic devices is placed on the left vertical wall of the enclosure. The right vertical wall is maintained at ambient temperature and all other walls are adiabatic. The results are presented in terms of flow structures, temperature distribution, and global average Nusselt number for various combinations of thermal controlling parameters, namely, the Richardson number (0 ≤ Ri ≤ 10), the Reynolds number (10 ≤ Ri ≤ 200), the heating section dimension (0. ≤ ε ≤ 0.7), and the relative height of the openings B = h/L = 1/8. It is found that for the low Reynolds number the heat transfer process is carried out only by conduction. On the other hand, the highest thermal performance is achieved by reducing the heating section dimension. [ABSTRACT FROM AUTHOR]

Mixed convection heat transfer in a 3-D ventilated cavity is studied numerically using finite volume method. The results are presented in terms of streamlines, temperature distribution, velocity fields, and average Nusselt number for different combinations of thermal and geometrical controlling parameters, namely, Reynolds number, Re = 100, Richardson number (0.01 ≤ Ri ≤ 10), relative height of the openings (B = h/L = 1/8) and relative width (0.5 ≤ A = w/L ≤ 1). The obtained results show that the flow intensity and the heat transfer rate can be significantly improved by an optimal choice of the mentioned parameters. [ABSTRACT FROM AUTHOR]

In this article unsteady 3-D MHD boundary layer flow and heat transfer analysis with constant temperature and constant heat flux in a porous medium is considered. The boundary layer flow is governed by a bi-directional stretching sheet. Similarity transformations are used to transform the governing non-linear partial differential equations to ordinary differential equations. Analytical solutions are constructed using homotopy analysis method. Convergence analysis is also presented through tabular data. The quantities of interest are the velocity, temperature, skin friction coefficient,t and Nusselt number. The obtained results are validated by comparisons with previously published work in special cases. The results of this parametric study are shown graphically and the physical aspects of the problem are discussed. [ABSTRACT FROM AUTHOR]